Process for the manufacture of ammonia



Patented June 24, 1930 UNITED STATES PATENT OFFICE CHARLES unrnn, or GENEVA, SWITZERLAND, ASSIGNOR 'ro sooIETE nnrunns MINIERESET rnnns'rnrnnnns, or PARIS, r'nnncn, A CORPORATION on nnancn rnocnss non THE MANUFACTURE or Ammonia I No Drawing. Original application filed January 2, 1926: Serial No. 79,039, and in France January 8,

1925. Divided and this application filed June 2, 1927. Serial Nm 196,152.

This application is a division of applicants copending application Serial No. 79,039, filed January 2, 1926, and entitled Process for the manufacture of metallicnitrides and relates to the synthetic production of ammonia.

In known processes,- such as the Haber process, for the synthetic manufacture of ammonia, iron nitride is produced from the nitrogen contained in a mixture of hydrogen and nitrogen, and is then decomposed in the presence of alumina through the hydrogen in the mixture. To effect such reaction it has been found necessary to have very high pressures (Haber indicates a minimum pressure of 250 kg/cm In the synthetic manufacture of ammonia it has also been tried directly to produce the nitride of iron or of metals of the iron group at a less high pressure, but even when employing high temperatures of for example 1,400 C.,'it has been found impossible to produce iron nitride as it disassociates into its elements at a temperature lower than that necessary for its formation.

According to this invention, ammonia is produced at a relatively low pressure by causing a hot mixture of h drogen and ni-. trogen to pass over iron, nic el, cobalt, tungsten.or molybdenum or mixtures thereof admixed with a compound of lithium contain-' ing nitrogen and either alumina, magnesia, or lime, or mixtures thereof.

I For exam le, a mixture of hydrogen and nitrogen is at a temperature of 550 to 600 0. passed over a mixture of three-parts of iron powder, two parts of lithium nitride and 5 to 10% 'by weight of alumina. Am-' monia is formed at a pressure of the order of atmospheric pressure.

In place of lithium nitride another .compound of lithium containing nitrogen may be em loyed, such as lithium amide, for examp e. The iron may be replaced by either nickel, cobalt, tungsten or molybdenum.

In the following claims where alumina is specified as one of the elements of the catalyst, it is to be understood that other equivalent oxides, such as lime or magnesia, or

mixtures of them may be used instead.

While the process constitutin the subject matter of the present invention as been describedin detail,'it is to be expressly under- I stood that the invention is not limited there-' with hydrogen, and a compound from the group consisting of alumina, magnesia and lime".-

2.VA' process for the manufacture of ammoma which consists in causing a, mixture of heated nitrogen and hydrogen to react in the presence of at least one metal of the iron group, lithium nitride, and at least one compound from the group consisting of alumina, magnesia and lime.

3. A process for the manufacture of ammonia which consists in causing a mixture of heated nitrogen and hydrogen to react in the presence of at least one metal of the iron group, a lithium nitrogenated compound which does not react when heated with hydrogen, and aluminum oxide.

4. A process for the manufacture of ammonia which-consists in causing-a mixture of heated nitrogen and hydrogen to react in the presence of iron, a lithium nitrogen compound which does not react when heated with hydrogen, and a compound from the group consisting of alumina, magnesia and lime.

5. A process for the manufacture of am-.

moniawhich consists in causing a mixture of heated nitrogen and hydro en to react in the presence 0 a metal of t e iron group, lithium nitride, and alumina.

In testimony whereof I have afiixed my signature.

CHARLES URFER. 

